guardrail vs paling

guardrail

noun
  • A rail set alongside a dangerous place as a barrier, to improve safety. 

  • Any barrier designed to prevent accidents or mistakes. 

paling

noun
  • A pointed stick used to make a fence. 

  • A fence made of galvanized sheeting. 

  • A fence made of palings. 

How often have the words guardrail and paling occurred in a corpus of books? (source: Google Ngram Viewer )